Due to the fast destruction of the ozone layer in the sky, which is caused by a Fluorochloride Compound (CFC) evaporating from the earth environment, over forty countries worldwide signed the Montreal Treaty in 1987 to prohibit further use of CFC and other related materials before the end of this century. Yet, despite an urgency to use the non-harmful replacement of R134a, many automobiles and other refrigeration devices still use the CFC like R-12 and R-22.
The Industrial Technology Research Institute of the Republic of China invented a Recovery and charging system for refrigerant (Taiwan Patent Publication No. 181617) for use in manufacturing factories, and is now also available for commercial use. However, such system has is proven to be ineffective due to the low recovery speed and the frequent breakdown of the compressor caused by over-heating. Subsequently, the manufacturing factories were forced, with a great degree of urgency, to seek a new replacement system.
After making numerous tests and large investments, a solution has been is reached that enables the applicant to double the speed of the recovery.
FIG. 1 is a the flow chart drawing of the recovery and charging system for refrigerant. The refrigeration and air conditioning system used in automobiles and elsewhere are omitted from the drawing. The refrigerant is recycled in the storage tank 10, and then is used to charge refrigeration and air conditioning units. The components of the system are indicated by particular reference numbers as follows: connecting tubes 20, a flow direction control device 30, a vacuum pump 50, a heat exchanger 60, an air vent device 70 and a dryer 80. The connecting tubes 20 include a low pressure inlet tube 21 and a high pressure inlet tube 22, through which refrigerant is sent to charge refrigeration and air conditioning systems (not shown) each of which consists of a compressor, a condenser, a dryer, an expansion valve and an evaporator.
The flow direction control device 30 is comprised of solenoid valves 31, 32, 33, 34, 35, 36, 37 and 38, and a check valve 39 provided between solenoid valves 32, 33, 34 and 36 to control the flow direction of the refrigerant. The control device 30 is connected to both the connecting tubes 20 and the storage tank 10.
The compression device 40 is comprised of a coil heat exchanger 99 and a compressor 42. A front oil separator 43 is provided between the coil heat exchanger 99 and a compressor 42 to separate the refrigeration oil mixed in together with the refrigerant. A rear oil separator 44 is provided after the compressor 42 to return the refrigeration oil in the refrigerant at the compressor outlet. The whole compression device 40 is connected to the flow direction control device 30. Vacuum pump 50 is also connected to flow direction control device 30 by means of a check valve 51 to suck out any uncondensable gas remaining in the refrigeration and air conditioning system. Air heat exchanger 60 is connected to the flow direction control device 30 and the compression device 40 respectively by a check valve 61. Another end of air heat exchanger 60 is also connected to the storage tank 10 by the flow direction control device 30.
Besides, another end of the air heat exchanger 60 is connected to the flow direction control device 30 by an expansion valve 62, and also to the storage tank 10 by a check valve 63, air vent device 70, a dryer 80 and sight glass 81. The expansion valve 62 reduces pressure and controls the flow more effectively when the charging refrigerant flows out of the storage tank 10. This allows the refrigerant to completely evaporate in the heat exchanger 60. The dryer 80 filters out contaminants, water or acid contained in the refrigerant, while the wet indicator on the sight glass 81 indicates whether the dryer needs to be replaced. The air vent device 70 is comprised of a pressure gauge 71, a pressure control switch 72, a solenoid valve 73 and a receiver 74, so that the remaining uncondensable gas in the refrigerant is expelled through the pressure control switch 72 and the solenoid valve 73. This prevents the gas from entering the storage tank 10.